Highly Enantioselective Intermolecular Iodo- and Chloroamination of Enecarbamates Catalyzed by Chiral Phosphoric Acids or Calcium Phosphate Salts
摘要:
Highly enantio- and diastereoselective vicinal chloro- and iodoamination reaction of enecarbamates catalyzed by chiral phosphoric acids or chiral calcium organophosphates are reported. The approach described herein provides efficient access to cis-chloro and cis-iodoaminals in good yields and excellent enantioselectivities (up to 99% ee). The resulting products are converted readily into highly important trans-azidoaminals.
Catalytic Asymmetric Synthesis of Cyclopentyl β‐Amino Esters by [3+2] Cycloaddition of Enecarbamates with Electrophilic Metalloenolcarbene Intermediates
作者:Yongming Deng、Matthew V. Yglesias、Hadi Arman、Michael P. Doyle
DOI:10.1002/anie.201605438
日期:2016.8.16
Chiral cyclopentyl β‐amino esters are formed catalytically by [3+2] cycloaddition reactions of enecarbamates with electrophilic metalloenolcarbenes in high yield with up to 98 % ee and excellent diastereocontrol. Use of β‐silyl‐substituted enoldiazoacetates with a chiral dirhodium catalyst and trans‐β‐arylvinylcarbamates are optimal for this transformation, which occurs with hydrogen‐bond association
Cerium(IV) Ammonium Nitrate Mediated Three-Component α-Allylation of Imine Surrogates
作者:Mathieu Bekkaye、Géraldine Masson
DOI:10.1021/ol5004143
日期:2014.3.7
A general and practical CAN-mediated oxidative radical alpha-coupling reaction of various imine surrogates with allylsilanes has been described. This multicomponent process affords beta-allylated alpha-carbamido ethers as stable imine precursors in respectable yields under mild conditions.